6-7 years recap is a bit much....
major points:
Server merge flow goes like this
Lintra => Valdes
SEA requiem closes
Korean server => Valdes
Valdes + Hammerine = Trifri (PK) (Requiem development shifts from Korean to US control)
Facebook Only Nova server arrives (no Pk)
Few months ago they offered a account cloning option for players to make copy of trifri or nova account onto other server. that ended and there are no options for server switching of accounts anymore.
Nova and Trifri now available on both FB and client (theres also a webpage based system to play requiem without client - Kalydo).
Level Cap is 90 at the moment.
Since Numeran map, no new maps have been added. Crescent has come back as a Nightmare monster filled map for all levels.
level 1-25ish questing is heavily streamlined to let new players enter game easier without as much grind.
leveling is significantly easier than 2008. with events and xp scrolls, you could max lvl in 1 day (if you reeeealllly wanted).
lvl 1-75 has no major new content. but 75-90 has several, these include
Secret Temple mini world/ dungeon. Altar of Sacrifice 3 boss raid and the super long Erunil's Tower. all for lvl 80+. Voxyon is latest raid boss.
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Skills? theres a long history of changes. significant updates to skills and classes is set to come in next major update (my guess is maybe january).
Mall point invested gear is everywhere and you cant seriously compete in pvp without investing as well. prepare for 1 shot deaths everywhere...
also, due to new gear and enchants that are somewhat overpowered, any class could do significant damage. mages obviously more dangerous simply due to aoes.
if you want to know more, ask specific questions or else you need to play and see for yourself.
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no new races nor any sight of them. classes have been redefined over time, mostly melee classes and xenoa classes have changed the most.